Store › Pentair GRO-50EN 1:1 Membrane Image 1 of 1 Pentair GRO-50EN 1:1 Membrane $99.00 Pentair GRO-50EN Super High Efficiency 1 to 1 ratio, 50 GPD Encapsulated Membrane Element. Requires 150ml Flow Restrictor Quantity: Add To Cart Added! Pentair GRO-50EN Super High Efficiency 1 to 1 ratio, 50 GPD Encapsulated Membrane Element. Requires 150ml Flow Restrictor Reviews Reviewer Name Review Date Star Rating Description Posted on Etsy Product Show More You Might Also Like Standard 24 - 75 GPD RO Membrane from $49.00 Reverse Osmosis Dual Wrench $9.00 Standard 5 Stage RO Filter Kit - ALK $89.00 Flow Restrictor with 1/4" Quick Connect Ports. $10.00 Sani-System for RO .25oz $5.00